Silencer



V. OLDBERG March 13, 1934.

SILENCE'R 1-932 2 Sheets-sheaf 1 Filed Nov. 29

INVENTQR ATTOR Y V. OLDBERG March 13, 1934.

SILENCER R O T N E V m ATTORNEY Patented Mar. 13, 1934 I UNITED STATES SILENCER Virgil Oldberg, Detroit, Mich., assignor to Oldberg Manufacturing Company, Detroit, Mich acorporation of Michigan Application November 29, 1932, Serial No. 644,852

6 Claims.

This invention relates to silencers and more particularly to silencers used in connection with gases exhausted from internal combustion engines.

The invention aims to provide a silencer which. is much more satisfactory of operation than silencers at present known and possessing novel features of construction and arrangement which will be more specifically brought out in the following detailed description of the silencer, reference being had to the appended drawings showing a preferred embodiment; In the drawings:

Figure 1 is an elevational section of the embodiment, as if on the line v11 of Figure 2;

Figure-2 is a transverse section as if on the line 22 of Figure 1;

Figure 3 is a plan section, as if on the line 3-3 of Figure 4;

Figure 4 is a transverse section, as if on the line 44 of Figure 3;

Figure 5 is a diagrammatic perspective view of the device. I

Referring to the drawings, it will be seen that the silencer includes an outer shell or casing 10 of a desired length in which are disposed three tangentially contacting intermediate shells 11, 12, and 14, somewhat shorter than the outer shell or, casing and arranged to be coextensive, substantially as indicated. Centrally disposed within the intermediate shells are through shells 16, 1'7, and 18, the annular spaces between the through shells and the intermediate shells containing sound wave attentuating means, such as the cones 20. The through shells, throughout substantially their entire area, are covered with a plurality of minute, outwardly extruded perforations 22 (only a few of which are shown) communicating the through passages in the through shells with the cone-containing annular spaces therearound and within the intermediate shells.

Each of the intermediate shells is provided with one or more openings or throats 24-45-26 communicating the interior thereof with one of the three relatively isolated sound wave attenuatlng chambers 282930 in the outer shell. Throats 2425 for shells 16 and 17 are at the left hand end of the silencer and open into chambers 30 and 28, respectively, while the throat 26 for shell 18 is at the right hand end and opens-into chamber 29. The chambers 28, 29, and 30 are isolated by the tangentially engaging shell surfaces.

Disposed within the outer shell 10 and closing the ends of the intermediate shells are inner headers 31 and 32. The header 31 is provided with three flanged openings through which pass the through shells through shellgl'l being continued beyond the header 31 a considerable extent. The other header 32 is also provided with three openings, these also receiving the open ends ofthe through shells, with through casing 16 projecting beyond header 32 a considerable extent. There are also disposed in the outer shell '10, two end headers 34 and 35, the former of which is provided with a sleeve 36 receiving the extended end of through shell 17, and the latter of which is provided with a sleeve 37 receiving through shell 16. The cooperating headers form end chambers 38 and 39 communicating shells 18. and 16, and 17 and 18, respectively.

It will be observed at this time that various engaging parts of the mufiler are welded to one an other, in any desired manner. Non-welded, slip type, expansion joints are provided at the junc ture between through shells 1'7 and 16, and sleeve 36 and sleeve 37, these joints permitting relative movement between the through shell ends and the sleeves, caused by relative expansion of the parts.

As previously described, the silencer disclosed is of the through or low back pressure type, that is tosay at no time do the coursing gases encounter such obstructions as would tend to baffie them and build up back pressure. However, while the silencer is of the low back pressure type, the pressure impulses therein are broken up in at least two places due to the reverse turns provided by the gases as they pass from shell 17 through expansion chamber 39 and into shell 18, and as they 1 pass from shell 18, through expansion chamber 38, and into shell 15.

Still further, though the silencer is of the through type, the reverse turns effectively break up any emerging flames and accordingly eliminate the necessity of providing a flame preventor i or the silencer.

Still further, it will be observed that the effective length of .the silencer, which is the aggregated lengths of the through shells, is about three times the actual length of the silencer, and accordingly, the silencer may be used in connection with engines requiring a long silencer, even though the longitudinal space allotted for the silencer is comparatively small.

An important feature of the invention is the rigidity of the silencer. It will be observed that the outer casing is braced by the three tangensilencer is facilitated because of the elimination of the necessity of manually locating the shells with respect to the heads. In the construction disclosed, units, each of which includes an intermediate shell, a through shell, and cones, locate themselves with respect to the headers because of the projecting through shells seating in the flanged openings of the headers. Further, not only do such units locate themselves automatically but they maintain themselves in assembled position with respect to the heads during welding operations and thus facilitate such operations.

. Still further, problems arising from expansions of the parts due to heating are well eliminated because of the slip joints provided at the juncture of the through shells and the header sleeves.

Still further, it will be observed that each intermediate shell opens into a chamber in which sound waves may be attenuated and that the construction provides three relatively isolated chambers, one for each intermediate and through shell unit, into each of which, in one isolated zone, open the throats.

Now having described a preferred embodiment of the invention, selected by way of example, reference will be had to the claims which follow for a determinationof the scope of the invention.

I claim:

1. In a silencer, means providing an inlet and an outlet therefor, an outer casing, parallel units each having an outer shell of curved cross section disposed therein, said shells tangentially'engaging one another, and the casing to form relatively isolated chambers, each chamber communicating with the interior of a unit to provide a resonance chamber therefor, eachof said outer shells having a perforated through shell nested therein, and sound wave attenuating means between the shells, and means providing expansion chambers at the ends of the casing, each communicating ends of throughshell interiors of two units.

2. In a silencer, means providing an inlet and an outlet therefor, an outer casing, end headers and intermediate headers therefor, parallel units each having an outer shell of curved cross section disposed therein, and connecting the intervmediate headers, said outer shells of said units tangentially engaging one another and the casing to form relatively isolated chambers, each chamber communicating with the interior of a unit to provide a resonance chamber therefor, each unit having a perforated through shell nested within said outer shell, and sound wave attenuating means between the shells, the sets of headers providing expansion chambers, at the ends of the casing, each communicating ends of through shell interiors of two units.

3. In a silencer of the retroverted passage type, an outer casing, means providing expansion chambers at the ends thereof, means providing an inlet and an outlet therefor, and means providingparallel through-flow units and mechanically connecting the chambers, the units being of curved cross section andbeing in tangential, relative bracing, engagement with one another and with the casing, and each being lined with means forming part of the unit providing means for providing sound wave attenuation, the units being shaped to provide isolated resonator chambers outside of them but inside the casing, with each resonator chamber communicating with the interior of a unit, each expansion chamber communicating the interiors of two units at their ends.

4. In a silencer of the retroverted passage type, an' outer casing, means providing expansion chambers at the ends thereof, means providing an inlet and an outlet therefor, and means providing parallel through-flow units and mechanically connecting the chambers, the units being of curved cross section and being in tangential, relative bracing, engagement with one another and with the casing, and each including an outer shell, transverse diaphragms therein, and an inner through shell passing through them, and having many perforations, the-units being shaped to provide isolated resonator chambers outside of them but inside the casing, with each resonator chamber communicating with the interior of a unit, each expansion chamber communicating the interiors of two units at their ends.

5. In a silencer of the retroverted passage type, an outer casing, means providing expansion chambers at the ends thereof, means providing an inlet and an outlet therefor, and means providing parallel through-low units and mechanically connecting the chambers, the units being of circular cross section and being in tangential, relative bracing, engagement with one another and with the casing, and each being lined with means form ing part of the unit providing means for providing sound wave attenuation, the units being shaped to provide isolated resonator chambers outside-of them but inside the casing, with each resonator chamber communicating with the interior of a unit, each expansion chamber communicating theinteriors of two units .at their ends.

6. In a silencer of the retroverted passage type, an outer casing, means providing expansion chambers at the ends thereof, means providing an inlet and an outlet therefor, and means providing parallel through-flow units and mechanically connecting the chambers, the units being of circular cross section and being in tangential, relative bracing, engagement with one another and with the casing, and each including an outer shell, transverse diaphragms therein, and an in- VIRGIL OLDBERG. 

